1. Field of the Invention
This invention relates to a wax polish composition, such as a wax polish composition for pharmaceutical tablets and food/confectionery pieces.
2. Description of the Prior Art
Conventional wax polish compositions are solutions of wax in an organic solvent such as carbon tetrachloride or ether. However, these solvents give rise to processing problems in the application of the polish to pharmaceutical tablets or confectionery pieces. For example, the removal of waste organic solvent vapor formed during the polishing process from exhaust air streams is very expensive, and an increasing number of countries do not allow vapors of organic solvents to be vented directly into the atmosphere. Further, many organic solvents are dangerous fire hazards and toxicity hazards to process workers. Moreover, inadvertent over-use of such wax solutions may spoil the product by the adhesion of excess wax to the surface.
If conventional wax polishing is performed in the presence of water, the surface of the tablet or piece to which the wax polish has been applied is usually subjected to over-washing which causes spoiling of the tablet's surface.
Because of the problems associated with the use of organic solvents, Colorcon developed an aqueous wax polish composition which is disclosed in Jordon U.S. Pat. No. 5,389,129 which issued on Feb. 14, 1995 and which is incorporated herein by reference. The aqueous wax polish composition disclosed in U.S. Pat. No. 5,389,129 provides an excellent wax coating for coating pharmaceutical tablets and food/confectionery items to impart a gloss thereto without dissolving the surface of the substrate with resultant deleterious effects on the finished product appearance. However, this aqueous polish composition may thicken during storage under certain conditions when stored for a long period of time.